By Frida Ghitis – 2016-04-30 17:27 GMT –  (CNN) — Last Saturday night, the Dutch journalist Ebru Umar was reportedly resting at her vacation home in the Turkish resort town of Kusadasi when she heard a knock at the door. Umar, a fierce critic of Turkish President Recep Tayyip Erdogan, was about to become an example of the very practices against which she has been fulminating in her newspaper columns and her Twitter account.”Police at the door. No joke,” she tweeted.

Turkish police reportedly detained her for 15 hours, and questioned her about tweets in which she quoted her own articles criticizing Erdogan. By Sunday afternoon she had been released, but was ordered not to leave the country while Turkish authorities decide whether to prosecute her under a law that makes it a crime to insult the President.

The move marked one more step in Erdogan’s determined march to crush dissent. But what is even more notable is that Umar is a Dutch citizen (as a child of Turkish immigrants she also holds Turkish citizenship, which she reportedly says she wants to renounce) but was detained in Turkey over work published in the Netherlands. Erdogan’s dismantling of press freedoms at home is deeply troubling, but his attacks against free expression in Europe and in the United States are unacceptable.

This is happening despite the fact that for many years, Erdogan was hailed as an example of a moderate, successful, democratically-minded Muslim leader. Indeed, speaking in 2009, President Barack Obama praised Erdogan, and Turkish democracy more generally.But 13 years after rising to power, Erdogan has apparently lost his fondness for democracy. Turkey now holds one of the world’s lowest rankings for press freedom, while hundreds of journalists have been charged or dismissed over news stories and books. Indeed, Turkey’s justice minister said government prosecutors may be pursuing some 1,800 cases over alleged insults aimed at Erdogan — and that is just since 2014, when he became president after serving as prime minister for more than a decade.

The government recently seized one of the country’s most popular newspapers, Zaman, owned by a political rival. After changing hands, Zaman has predictably joined the monotonous pro-Erdogan chorus.This would be worrying enough if it affected only Turkey. But it doesn’t. The government has detained journalists from Brazil, Germany and the United States, among other countries, some of whom were covering the war in Syria and the historic refugee crisis.

It is that refugee crisis — and the war that created it — that has given Erdogan leverage with the West, and which has likely made Western leaders reluctant to properly take him to task. Yes, he agreed to stop the refugee flow in exchange for billions of dollars in aid and other concessions, but he has his hand on the lock and is able to open the gates and allow hundreds of thousands more refugees to head for Europe if he chooses.

Fearful of another giant wave of refugees, German Chancellor Angela Merkel recently caved to Turkish demands to allow the possible prosecution of a German comic who mocked the Turkish president. Jan Bohmermann read a poem on German television accusing Erdogan of having, shall we say, excessive affection for animals. The reaction from Turkey’s deputy prime minister was swift: “The Republic of Turkey demands that this impertinent man is immediately punished for insulting a president.” He added that the poem was “a serious crime against humanity.” Merkel allowed the prosecution to go forward under an obscure law, but her move was met with an explosion of anger across Europe, with one British magazine responding by launching an “Insult Erdogan” competition. But this is not the only example of Turkish overreaction — the Turkish consulate also demanded that Geneva remove from an exhibition a photo showing a banner that blames Erdogan for the death of a Turkish teenager during anti-government protests in Istanbul. Unlike the German government, the Geneva municipality has no obvious vulnerability to retaliation by Erdogan and refused to comply with the Turkish demand. Yet another Turkish attempt to stifle criticism raised the ire of the Dutch — including journalist Ebru Umar. Last week, the Turkish consulate in the Dutch city of Rotterdam sent an email to Turkish groups asking them to report back on any insults aimed at Erdogan. After the outcry, the embassy claimed it had all been a misunderstanding.

And the bully tactics by Turkey’s government were also on display in the United States late last month, when Erdogan’s security detail was reported to have manhandled journalists and started scuffling with anti-Erdogan protesters, trying to rip the banners out of their hands. In a video captured by a Turkish journalist, a man identified in various media as a U.S. Secret Service agent is heard confronting one of Erdogan’s bodyguards, telling him to “act like an adult” and that “this is America.”

For now, Ebru Umar is stuck in Turkey, awaiting the outcome of her case. The Netherlands says it is working for her release. However, Dutch Foreign Minister Bert Koenders reportedly told Parliament that the government cannot guarantee the safety of its citizens who travel to Turkey, a popular vacation destination.That another state is warning its citizens about traveling to Turkey should give Erdogan pause — his actions risk undermining the crucial tourism industry. But there must be more. Turkey still aspires to become a member of the European Union, and Erdogan should be told in no uncertain terms that his actions make that impossible.It is understandable that Europe is concerned about retaliation — not just over the flow of refugees, but because Turkey is also an ally in the fight against ISIS, allowing NATO jets to be based there. But democracies must defend free expression (and Europe should also remember that Erdogan needs the refugee deal, too).

Freedom of speech is already disappearing in Turkey, a sign that democracy, too, is dying there. But even if other nations will not push back forcefully about what Erdogan is doing in his own country, they should at the very least defend their citizens’ right to free speech from Erdogan’s assault — and make clear to Turkey’s president that his crackdown will have consequences.